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Microscopic methods in life sciences are of tremendous importance for visualization cellular and tissue structures. In recent years, development has reached a revolution in order to overcome the resolution barrier given by the diffraction limit was broken by new microscopy concepts. That enable resolution limit down to about 10 nm and the visualization of cellular structures and molecular interactions reveal new understanding in biological processes. Due to tremendous efforts in the development of super-resolved fluorescence microscopy, The Nobel Prize in Chemistry for 2014 was awarded to Eric Betzig, Stefan W. Hell, and to William E. Moerner.

These super-resolution microscopy principles are based on several technological approaches. Conventional light microscopy enables a resolution limit of about 250 nm in the x- and y- direction and 450 – 700 nm in the z –direction. Super-resolution techniques are overcome the resolution-limit (Point-spread function), at least by a factor of 2. The resolution of super-resolution microscopy depends on the number of points that can be resolved on the structure of interest. Crucial for a successful super-resolution imaging is the choice of fluorescent probe. Brightness and high contrast ratio between the states are of great importance. In most super-resolution methods, the states of the probe must be controllable, reversible or irreversible, switchable between a light or a dark state. Depending on the super-resolution method, further photo-physical criteria the probe must be fulfilled. Established techniques are, for example:

STED (Stimulated emission depletion)

GSDIM (Ground State Depletion)

PALM (Photoactivated localization microscopy)

STORM (Stochastic optical reconstruction microscopy)

RESOLFT (reversible saturable optical (flurorescence) transitions)

Sigma now offer the superior series of Abberior dyes, that are especially designed and tested for super-resolution microscopy such as STED, RESOLFT, PALM, STORM, GSDIM and others. Abberior STAR, Abberior CAGE, Abberior FLIP, Abberior RSFP – the specific requirements of the super-resolution techniques are served with dedicated dye series. These Dyes are developed and produced by Abberior GmbH. Stefan Hell is it’s Co-founder.

Super-resolution microscopy depends on fluorescent labels more than any other fluorescence imaging technique. Manufactured by Abberior, the STAR, CAGE and FLIP dyes as well as RSFPs are exceptionally bright and photostable and provide optimized photoswitching for RESOLFT and PALM/STORM imaging. They are the only commercially available dyes that are tailored specifically to the needs of super-resolution microscopy.

Abberior dyes are also exceptionally well suited for confocal microscopy, epifluorescence imaging and single molecule applications. Basically all fluorescence applications which depend on a good signal to noise ratio and low background benefit from the novel Abberior dyes.

Fig2: Two subunits of the nuclear pore complex were immunolabelled using antibodies against gp210 and antibodies with multiple specificities (PAN4/5) and secondary antibodies coupled to Abberior STAR580 and Abberior STAR635P. Note that gp210 is localized in an eightfold symmetric structure at the rim of the nuclear pore complex. Imaged with the Abberior Instruments STEDYCON (compact line).